WASHINGTON - The Pentagon said its $34 billion ground-based system to defend the continental U.S. successfully intercepted a dummy incoming missile for the first time since 2008.

The test, using a conventional warhead made by Raytheon, took place on Sunday over the Pacific Ocean, the Defense Department said in an emailed statement. The interceptor missile made by Orbital Sciences was fired from Vandenberg Air Force Base in California. Boeing manages the ground-based missile defense program.

"This is a very important step in our continuing efforts to improve and increase the reliability of our homeland ballistic missile defense system," Vice Admiral James Syring, director of the Pentagon's Missile Defense Agency, said in the statement.

Two 2010 tests failed, as did one last July that used an older warhead that's on 20 of the 30 interceptors based in silos at Vandenberg and Fort Greely in Alaska.

The newest version of the warhead flown Sunday carried a redesigned inertial navigation unit and software upgrades, according to the Missile Defense Agency.

"We made the fixes needed to be made from the last test" and "we're looking forward to it," Rear Admiral John Kirby, the Pentagon spokesman, told reporters on Friday. He described the precision required as "like hitting a BB with a BB."

Defense Secretary Chuck Hagel has said that successful testing of the new warhead is a prerequisite for the Pentagon's plan to add 14 interceptors in Alaska by 2017 to counter what U.S. officials say is a growing threat from North Korea.

A long-range interceptor launched from Vandenberg hit an intermediate-range ballistic missile target launched from the U.S. Army's Reagan Test Site on Kwajalein Atoll in the Republic of the Marshall Islands on Sunday, according to the Pentagon statement.

The test marked the 65th successful intercept of 81 attempts since 2001 for the Ballistic Missile Defense System, according to the statement.

Syring told the Senate defense appropriations subcommittee this month that a non-interception test of the new warhead in January 2013 found that a redesign had damped vibrations that caused one of the 2010 failures. The other 2010 failure was caused by quality issues that Raytheon has corrected, the agency has said.

The agency stopped taking deliveries of warheads from Waltham, Mass.-based Raytheon after the 2010 failures.

In advance of the test, Laura Grego, a senior scientist at the Union of Concerned Scientists in Cambridge, Mass., had said in an emailed statement that even a success "would demonstrate little about the kill vehicle's capability and reliability."